Coupling calculation method and device for axial power deviation risk caused by fouling in pressurized water reactor

Abstract

The present application provides a method and device for coupled calculation of the risk of axial power shift caused by scale in a pressurized water reactor, including: using a first calculation module to simulate the thickness deposition of corrosion deposits and calculate the coolant temperature distribution in the axial direction of the fuel rod and the thickness distribution of corrosion deposits in the axial direction of the fuel rod; using a second calculation module to simulate the enrichment of boron elements inside the corrosion deposits and calculate the boron concentration distribution in each axial layer of corrosion deposits; using a third calculation module to simulate the axial power distribution of the fuel rod and calculate the scale-induced axial power shift value based on the corrosion deposit thickness distribution and the boron concentration distribution. The present application predicts the scale-induced axial power shift value by using a calculation method that couples multiple modules, multiple physical fields, and multiple scales, so as to solve the technical problem of how to comprehensively consider the effects of multiple scales and multiple physical fields to predict and analyze the corrosion deposit deposition.

Description

Technical Field

[0001] The present application belongs to the technical field of safety assessment and analysis of pressurized water reactor nuclear power plants, and specifically relates to a method and device for coupling calculation of the risk of axial power deviation caused by scale in a pressurized water reactor. Background Art

[0002] At present, the academic community mainly uses computational fluid dynamics (CFD) and other methods to simulate the thickness of corrosion deposits (CRUD) for the risk assessment of Crud Induced Power Shift (CIPS), and then predicts the CIPS risk based on the thickness of the corrosion deposits. First, due to the use of macroscopic CFD calculation methods, this method requires a long calculation time and cannot well predict the corrosion deposit deposition process at the micro-mesoscopic scale; secondly, the method of predicting CIPS risk based on thickness is relatively rough, and the axial power distribution of the fuel rod cannot be directly obtained, thereby quantitatively analyzing CIPS.

[0003] At the same time, some scholars have used empirical formulas to simulate the deposition process of corrosion deposits and predict the boron content inside the corrosion deposit layer based on the thickness of the corrosion deposits, thereby evaluating the CIPS risk. This method uses a large number of empirical parameters and fitting parameters, and cannot effectively predict the operating conditions of general pressurized water reactors.

[0004] Therefore, how to comprehensively consider the effects of multiple scales and multiple physical fields to predict and analyze the deposition of corrosion deposits has become a difficult problem in existing technologies. Summary of the invention

[0005] In view of this, the present application is committed to providing a coupled calculation method and device for the risk of scale-induced axial power deviation in a pressurized water reactor. By adopting a calculation method that couples multiple modules, multiple physical fields and multiple scales, the numerical value of the scale-induced axial power deviation is predicted to solve the technical problem of how to comprehensively consider the effects of multiple scales and multiple physical fields to predict and analyze the deposition of corrosion deposits.

[0006] The first aspect of the present application provides a coupled calculation method for the risk of axial power shift caused by scaling of a pressurized water reactor. The coupled calculation method for the risk of axial power shift caused by scaling of a pressurized water reactor comprises: using a first calculation module to simulate the thickness deposition of corrosion deposits, and obtaining the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit deposition thickness distribution of the fuel rod through axial grid iteration calculation; using a second calculation module to simulate the enrichment of boron elements inside the corrosion deposits, and according to the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit deposition thickness distribution of the fuel rod output by the first calculation module, solving the temperature, pressure and concentration control equations for each axial layer of corrosion deposit deposition, and obtaining the boron concentration distribution in each axial layer of corrosion deposits; using a third calculation module to simulate the axial power distribution of the fuel rod, and according to the corrosion deposit thickness distribution output by the first calculation module and the boron concentration distribution output by the second calculation module, for each layer of corrosion deposit deposition, calculating the average boron concentration, generating the input file required by the open source neutron calculation software OpenMC, and performing neutron flux and reaction power calculations, and obtaining the scale-induced axial power shift value.

[0007] In a specific embodiment of the present application, the method for calculating the risk coupling of scale-induced axial power offset of a pressurized water reactor also includes: if the scale-induced axial power offset value is not greater than a set safety threshold, the scale-induced axial power offset value is input into the first calculation module by a third calculation module to perform the scale-induced axial power offset coupling operation for the next time step; if the scale-induced axial power offset value is greater than the set safety threshold, the third calculation module is used to issue an alarm and end the simulation.

[0008] In a specific embodiment of the present application, the temperature, pressure and concentration control equations of each axial layer of corrosion deposits are solved to obtain the boron concentration distribution in each axial layer of corrosion deposits, including: for each axial layer of corrosion deposits, the chimney area in the corrosion deposits is modeled and gridded using a second calculation module using a microchannel model, and the temperature control equation, pressure control equation and solute concentration control equation are discretely solved using the finite volume method to obtain the boron concentration distribution in each axial layer of corrosion deposits.

[0009] In a specific embodiment of the present application, the temperature control equation inside the corrosion deposit is: The pressure control equation inside the corrosion deposit is: , , where: - the permeability of the dirt deposits, - dynamic viscosity of the coolant, ; The concentration control equation inside the corrosion deposit is: , where: ——Diffusion coefficient of solute in solvent; T——temperature; P——pressure; C——concentration; ——Flow field velocity vector.

[0010] In a specific embodiment of the present application, the second calculation module is used to simulate the enrichment of boron in the corrosion deposit, including: using the second calculation module to divide the boundary of the corrosion deposit calculation area into four parts to simulate the enrichment of boron in the corrosion deposit, the four parts include the corrosion deposit-coolant boundary, the corrosion deposit-chimney surface boundary, the corrosion deposit-cladding boundary and the corrosion deposit-corrosion deposit periodic boundary,

[0011] For the temperature boundary conditions of the temperature control equation, the boundary conditions of the corrosion deposit-coolant boundary are: , represents the heat exchange between the corrosion deposits and the coolant; the boundary condition of the corrosion deposit-chimney surface boundary is: , represents the temperature consistency condition between the corrosion deposit and the chimney surface; the boundary condition of the corrosion deposit-cladding boundary is: , represents the heat input from the fuel cladding; the boundary condition of the corrosion deposit-corrosion deposit periodic boundary is: , represents the zero gradient boundary condition; where: ——Equivalent thermal conductivity of corrosion deposits, ; ——Evaporation heat transfer coefficient of corrosion and fouling surface, ; T coolant ——Coolant temperature; T sat ——chimney surface temperature; - heat flux on the fuel rods, ; ——Boundary normal direction vector; For the pressure boundary condition of the pressure control equation, the boundary condition of the corrosion deposit-coolant boundary is: , which means that the upper part of the corrosion deposit is consistent with the coolant pressure; the boundary condition of the corrosion deposit-chimney surface boundary is: , represents the mass dissipation of the chimney surface due to evaporation; the boundary conditions of the corrosion deposit-cladding boundary and the corrosion deposit-corrosion deposit periodic boundary are: , represents the zero gradient boundary condition; where: - enthalpy of vaporization of the coolant, ; - Coolant pressure, ; ρ——coolant density; For the concentration boundary conditions of the concentration control equation, the boundary conditions of the corrosion deposit-coolant boundary are: , which means that the solute concentration in the upper part of the corrosion deposit is equal to that in the coolant; the boundary condition of the corrosion deposit-chimney surface boundary is: , which means that no solute is precipitated from the chimney surface; the boundary conditions of the corrosion deposit-cladding boundary and the corrosion deposit-corrosion deposit periodic boundary are: , represents the zero gradient boundary condition; where: C coolant ——Solute concentration in the coolant.

[0012] In a specific embodiment of the present application, the third calculation module is used to simulate the axial power distribution of the fuel rod, and according to the corrosion fouling thickness distribution output by the first calculation module and the boron concentration distribution output by the second calculation module, for each layer of corrosion fouling deposition, the average boron concentration is calculated, the input file required by the open source neutron calculation software OpenMC is generated, and the neutron flux and reaction power are calculated to obtain the scale-induced axial power offset value, including:

[0013] The third calculation module is used to integrate the corrosion deposit thickness distribution obtained in the first calculation module and the boron concentration distribution obtained in the second calculation module to generate the input file required by the open source neutron calculation software OpenMC. The axial power distribution of the fuel rod is obtained by calculation using the Monte Carlo method, and the scale-induced axial power offset value AO is calculated according to the following formula: , where: ——Power integral of the upper half of the fuel rod, ——Power integral of the lower half of the fuel rod.

[0014] The second aspect of the present application provides a coupled calculation device for the risk of axial power deviation caused by fouling in a pressurized water reactor, which comprises a first calculation module, a second calculation module and a third calculation module. The first calculation module is used to simulate the thickness deposition of corrosion deposits, and obtain the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod through axial grid iteration calculation. The second calculation module is connected to the first calculation module, and is used to simulate the enrichment of boron elements inside the corrosion deposits, and according to the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod output by the first calculation module, the temperature, pressure and concentration control equations of each axial layer of corrosion deposit deposition are solved to obtain the boron concentration distribution in each axial layer of corrosion deposits. The third calculation module is connected to the first calculation module and the second calculation module, and is used to simulate the axial power distribution of the fuel rod. According to the thickness distribution of corrosion deposits output by the first calculation module and the boron concentration distribution output by the second calculation module, for each layer of corrosion deposit deposition, the average boron concentration is calculated, the input file required by the open source neutron calculation software OpenMC is generated, and the neutron flux and reaction power are calculated to obtain the scale-induced axial power offset value.

[0015] The third aspect of the present application provides an electronic device, which includes a processor and a memory. The processor is used to execute a method for calculating the risk coupling of axial power deviation caused by scale in a pressurized water reactor according to the first aspect of the present application. The memory is used to store executable instructions of the processor.

[0016] In a fourth aspect, the present application provides a computer-readable storage medium on which executable instructions of a computer are stored. When the executable instructions are executed by a processor, a method for calculating the risk coupling of axial power deviation caused by fouling in a pressurized water reactor according to the first aspect of the present application is implemented.

[0017] The fifth aspect of the present application provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements a method for calculating the risk coupling of axial power deviation caused by scale in a pressurized water reactor according to the first aspect of the present application.

[0018] The beneficial effect of the technical solution of the present application is that: the embodiment of the present application divides the risk prediction of axial power deviation caused by scale into three calculation modules (i.e., the first calculation module, the second calculation module, and the third calculation module), uses the first calculation module to simulate the thickness deposition of corrosion deposits, uses the second calculation module to simulate the enrichment of boron elements inside corrosion deposits, and uses the third calculation module to simulate the axial power distribution of fuel rods, thereby predicting the power distribution of fuel rods, realizing the real-time simulation of the process of axial power deviation caused by scale, and enhancing the practicality of the program. Moreover, the calculation method has high calculation efficiency and fast calculation speed, and can be written in Python language, which is easy to implement and deploy on different devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a flow chart of a method for coupling calculation of the risk of axial power deviation caused by fouling in a pressurized water reactor provided in one embodiment of the present application.

[0020] Figure 2 The figure is a simplified schematic diagram of the process of a method for coupling calculation of the risk of axial power deviation caused by fouling in a pressurized water reactor provided in one embodiment of the present application.

[0021] Figure 3 The figure shows a schematic diagram of a boron enrichment calculation area and boundary conditions inside a CRUD provided by an embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] At least one embodiment of the present application provides a method for calculating the risk of axial power deviation caused by fouling in a pressurized water reactor, referring to Figure 1 and Figure 2 The coupled calculation method for the risk of axial power deviation caused by fouling in a pressurized water reactor includes the following steps.

[0024] S100: simulating the thickness deposition of corrosion deposits by using the first calculation module 1, and obtaining the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod by axial grid iteration calculation.

[0025] For example, given PWR operating parameters and material property parameters, fuel rod geometric parameters, fuel rod initial heat flux distribution and other parameters are input into the first calculation module 1, and the first calculation module 1 calculates the corrosion fouling deposition thickness distribution (CRUD thickness distribution) of the fuel rod axial direction according to these parameters. For example, the first calculation module 1 is based on the existing micro-mesoscopic multi-scale physical field coupling code, adds the influence of the nucleate boiling effect to the temperature, pressure control equations and boundary conditions, and uses a simplified CFD method to calculate the turbulent kinetic energy intensity and temperature distribution of the coolant at the macro scale, and calculates the corrosion fouling deposition rate and erosion rate by multi-scale joint solution, accurately simulating the deposition growth process of the corrosion fouling on the surface of the fuel rod. The specific calculation methods and models involved in this module have been described in the patent "Multi-scale coupling determination method and device for the fouling deposition process on the surface of the fuel rod in a pressurized water reactor (application number: CN202411421068.7)".

[0026] It should be noted that a pressurized water reactor can also be called a pressurized water reactor.

[0027] S200: The second calculation module 2 is used to simulate the enrichment of boron elements inside the corrosion deposits, and according to the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod output by the first calculation module 1, the temperature, pressure and concentration control equations of each axial layer of the corrosion deposit deposition are solved to obtain the boron concentration distribution in each axial layer of the corrosion deposits.

[0028] S300: The third calculation module 3 is used to simulate the axial power distribution of the fuel rod, and according to the corrosion deposit thickness distribution output by the first calculation module 1 and the boron concentration distribution output by the second calculation module 2, for each layer of corrosion deposit deposition, the average boron concentration is calculated, and the input file required by the open source neutron calculation software OpenMC is generated, and the neutron flux and reaction power are calculated to obtain the scale-induced axial power offset value.

[0029] It should be noted that the scaling-induced axial power deviation value calculated by the third calculation module 3 is the predicted fuel rod power distribution.

[0030] In view of the fact that the existing scale-induced axial power shift risk prediction methods mostly use risk assessment based on the thickness of corrosion deposits, which has the defect of large assessment errors, the present application embodiment divides the scale-induced axial power shift risk prediction into three calculation modules (i.e., the first calculation module 1, the second calculation module 2, and the third calculation module 3), uses the first calculation module 1 to simulate the thickness deposition of corrosion deposits, uses the second calculation module 2 to simulate the enrichment of boron elements inside corrosion deposits, and uses the third calculation module 3 to simulate the axial power distribution of fuel rods, thereby predicting the power distribution of fuel rods, realizing the real-time simulation of the scale-induced axial power shift process, and enhancing the practicality of the program. In addition, the calculation method has high calculation efficiency and fast calculation speed, and can be written in Python language, which is easy to implement and deploy on different devices.

[0031] In view of the defect that the existing safety analysis program of pressurized water reactors strongly relies on empirical parameters and empirical formulas, resulting in the defect that risk prediction is not flexible and timely, the embodiment of the present application is designed to bring the axial distribution of the thickness of the corrosion fouling calculated in the first calculation module 1 into the second calculation module 2 for boron enrichment analysis, and then the axial distribution of the thickness of the corrosion fouling and the distribution of the boron enrichment will be used as the input of the third calculation module 3. The calculation method involves the calculation of the boron enrichment process on the micro-mesoscopic scale, the prediction of the deposition process of the corrosion fouling on the mesoscopic to macroscopic scale, and the neutron calculation part is used to obtain the axial power distribution of the fuel rod. The mutual coupling analysis between the three calculation modules is used to calculate the scale-induced axial power offset value, so that the power distribution of the fuel rod is predicted by using a calculation method of multi-module, multi-physical field and multi-scale coupling, and the calculation model is more reasonable, reducing the dependence on empirical formulas and parameters. In addition, the calculation method can make the simulation results more accurate and reasonable by dynamically modifying the operating parameters.

[0032] In at least one embodiment of the present application, the method for calculating the coupled risk of axial power deviation caused by fouling in a pressurized water reactor further includes step S400.

[0033] S400: If the scale-induced axial power offset value is not greater than the set safety threshold, the scale-induced axial power offset value is input into the first calculation module 1 by the third calculation module 3 to perform the scale-induced axial power offset coupling operation for the next time step; if the scale-induced axial power offset value is greater than the set safety threshold, the third calculation module 3 is used to issue an alarm and end the simulation.

[0034] The embodiment of the present application adopts a solution of mutual coupling and timely updating between modules to complete the risk assessment of scale-induced axial power excursion within a certain time step, and then the new power distribution is re-input into the first calculation module 1 to carry out the risk assessment and analysis process of scale-induced axial power excursion for the next time step, so that the coupled calculation method of the risk of scale-induced axial power excursion of the pressurized water reactor is suitable for predicting and analyzing the phenomenon of scale-induced axial power excursion in the pressurized water reactor, thereby performing real-time evaluation and prediction of the risk of scale-induced axial power excursion, and realizing the full-link simulation analysis from CRUD deposition prediction to CIPS risk assessment. Through this coupling analysis between modules, the calculation method couples multi-physical processes at multiple scales, can perform real-time evaluation and prediction of the risk of scale-induced axial power excursion, reduces the dependence on empirical formulas and parameters, can be dynamically adjusted according to the actual operating status of the pressurized water reactor, and improves the flexibility of the scale-induced axial power excursion risk prediction and assessment system.

[0035] In at least one embodiment of the present application, reference Figure 3 Step S210 is a specific implementation method of "solving the temperature, pressure and concentration control equations for the corrosion deposits in each axial layer to obtain the boron concentration distribution in the corrosion deposits in each axial layer" in the above step S200.

[0036] S210: For each layer of corrosion deposits in the axial direction, the chimney area in the corrosion deposits is modeled and meshed using the microchannel model using the second calculation module 2, and the temperature control equation, pressure control equation and solute concentration control equation are discretely solved using the finite volume method to obtain the boron concentration distribution in each layer of corrosion deposits in the axial direction.

[0037] In at least one embodiment of the present application, the temperature control equation inside the corrosion deposit is: The pressure control equation inside the corrosion deposit is: , , where: - the permeability of the dirt deposits, - dynamic viscosity of the coolant, ; The concentration control equation inside the corrosion deposit is: , where: ——Diffusion coefficient of solute in solvent; T——temperature; P——pressure; C——concentration; ——Flow field velocity vector.

[0038] In at least one embodiment of the present application, the second calculation module 2 is used to simulate the enrichment of boron in the corrosion deposits, including:

[0039] The second calculation module 2 is used to divide the boundary of the corrosion deposit calculation area (i.e., the CRUD calculation boundary) into four parts for simulating the enrichment of boron elements inside the corrosion deposits. The four parts include the corrosion deposit-coolant boundary (upper boundary), the corrosion deposit-chimney surface boundary (left boundary), the corrosion deposit-cladding boundary (lower boundary) and the corrosion deposit-corrosion deposit periodic boundary (right boundary).

[0040] For the temperature boundary conditions of the temperature control equation, the boundary conditions of the corrosion deposit-coolant boundary are: , represents the heat exchange between the corrosion deposits and the coolant; the boundary condition of the corrosion deposit-chimney surface boundary is: , represents the temperature consistency condition between the corrosion deposit and the chimney surface; the boundary condition of the corrosion deposit-cladding boundary is: , represents the heat input from the fuel cladding; the boundary condition of the corrosion deposit-corrosion deposit periodic boundary is: , represents the zero gradient boundary condition; where: ——Equivalent thermal conductivity of corrosion deposits, ; ——Evaporation heat transfer coefficient of corrosion and fouling surface, ; T coolant ——Coolant temperature; T sat ——chimney surface temperature; - heat flux on the fuel rods, ; ——Boundary normal direction vector; For the pressure boundary condition of the pressure control equation, the boundary condition of the corrosion deposit-coolant boundary is: , which means that the upper part of the corrosion deposit is consistent with the coolant pressure; the boundary condition of the corrosion deposit-chimney surface boundary is: , represents the mass dissipation of the chimney surface due to evaporation; the boundary conditions of the corrosion deposit-cladding boundary and the corrosion deposit-corrosion deposit periodic boundary are: , represents the zero gradient boundary condition; where: - enthalpy of vaporization of the coolant, ; - Coolant pressure, ; ρ——coolant density; For the concentration boundary conditions of the concentration control equation, the boundary conditions of the corrosion deposit-coolant boundary are: , which means that the solute concentration in the upper part of the corrosion deposit is equal to that in the coolant; the boundary condition of the corrosion deposit-chimney surface boundary is: , which means that no solute is precipitated from the chimney surface; the boundary conditions of the corrosion deposit-cladding boundary and the corrosion deposit-corrosion deposit periodic boundary are: , represents the zero gradient boundary condition. Where: C coolant ——Solute concentration in the coolant.

[0041] In at least one embodiment of the present application, step S310 is a specific implementation of the above step S300.

[0042] S310: The third calculation module 3 is used to integrate the corrosion deposit thickness distribution obtained in the first calculation module 1 and the boron concentration distribution obtained in the second calculation module 2, and the input file required by the open source neutron calculation software OpenMC is generated. The axial power distribution of the fuel rod is obtained by calculation using the Monte Carlo method, and the scale-induced axial power offset value AO is calculated according to the following formula.

[0043] ;

[0044] Where: ——Integral power of the upper half of the fuel rod; ——Power integral of the lower half of the fuel rod; AO——Axial power offset value caused by fouling.

[0045] The formula can be used to obtain the risk value of axial power deviation caused by scaling of the pressurized water reactor in the current operating state. According to the guidelines of Westinghouse Electric Company, when When the scale-induced axial power deviation event occurs, it can be considered that a serious event has occurred, and the reactor needs to be shut down.

[0046] The coupled calculation method for the risk of axial power deviation caused by scale in a pressurized water reactor provided in the embodiment of the present application has verified the accuracy of the calculation model by comparing with domestic and foreign literature, and verified the feasibility of the calculation method by testing scenarios. Using the coupled calculation method proposed in the present invention, it is possible to reasonably simulate the deposition and growth of corrosion deposits, the boron concentration concentration process, and the fuel rod power distribution process during the operation of a pressurized water reactor, and give an early warning of the risk of axial power deviation caused by scale, which can be used for safety monitoring and prediction of pressurized water reactors.

[0047] At least one embodiment of the present application also provides a coupled calculation device for the risk of axial power deviation caused by fouling in a pressurized water reactor. The coupled calculation device for the risk of axial power deviation caused by fouling in a pressurized water reactor includes a first calculation module 1, a second calculation module 2 and a third calculation module 3. The first calculation module 1 is used to simulate the thickness deposition of corrosion deposits, and obtain the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit deposition thickness distribution of the fuel rod through axial grid iteration calculation. The second calculation module 2 is connected to the first calculation module 1, and is used to simulate the enrichment of boron elements inside the corrosion deposits, and according to the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit deposition thickness distribution of the fuel rod output by the first calculation module 1, the temperature, pressure and concentration control equations of each axial layer of corrosion deposit deposition are solved to obtain the boron concentration distribution in each axial layer of corrosion deposits. The third calculation module 3 is connected to the first calculation module 1 and the second calculation module 2, and is used to simulate the axial power distribution of the fuel rod. According to the thickness distribution of the corrosion deposits output by the first calculation module 1 and the boron concentration distribution output by the second calculation module 2, for each layer of corrosion deposit deposition, the average boron concentration is calculated, the input file required by the open source neutron calculation software OpenMC is generated, and the neutron flux and reaction power are calculated to obtain the scale-induced axial power offset value.

[0048] It should be noted that the device for calculating the risk coupling of axial power deviation caused by scaling of a pressurized water reactor is a calculation device corresponding to the method for calculating the risk coupling of axial power deviation caused by scaling of a pressurized water reactor in the above-mentioned embodiment, includes the corresponding technical features of the method for calculating the risk coupling of axial power deviation caused by scaling of a pressurized water reactor in the above-mentioned embodiment, can achieve the corresponding technical effects, and will not be repeated here.

[0049] At least one embodiment of the present application also provides an electronic device, which includes a processor and a memory. The processor is used to execute a method for calculating the risk coupling of axial power deviation caused by scale in a pressurized water reactor provided in any of the above embodiments of the present application. The memory is used to store executable instructions of the processor, such as application programs. The number of processors can be one or more. The application program stored in the memory may include one or more modules, each of which corresponds to a set of instructions. In addition, the processor is configured to execute instructions to execute the above-mentioned method for calculating the risk coupling of axial power deviation caused by scale in a pressurized water reactor.

[0050] The electronic device may also include a power supply component configured to manage power of the electronic device, a wired or wireless network interface configured to connect the electronic device to a network, and an input / output (I / O) interface. The electronic device may operate based on an operating system stored in the memory, such as Windows Server 2003. TM , Mac OSX TM , UnixTM , Linux TM , FreeBSD TM or similar.

[0051] At least one embodiment of the present application further provides a computer-readable storage medium on which executable instructions of a computer are stored. When the executable instructions are executed by a processor, a method for calculating the risk coupling of axial power deviation caused by fouling in a pressurized water reactor provided in any of the above embodiments of the present application is implemented.

[0052] A non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by the processor of the electronic device, enables the electronic device to execute the above-mentioned pressurized water reactor scale-induced axial power deviation risk coupling calculation method. The pressurized water reactor scale-induced axial power deviation risk coupling calculation method is executed by an agent program.

[0053] Those of ordinary skill in the art will appreciate that the algorithmic steps of each example described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0054] At least one embodiment of the present application further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements a method for calculating the risk coupling of axial power deviation caused by scale in a pressurized water reactor provided in any of the above embodiments of the present application.

[0055] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a computer program product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the calculation method for the risk coupling of axial power deviation caused by scale in a pressurized water reactor of each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program check codes.

[0056] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0057] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the term "comprising" only indicates that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0058] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0059] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A coupled calculation method for the risk of axial power deviation caused by fouling in a pressurized water reactor, characterized in that: include: The first calculation module is used to simulate the thickness deposition of corrosion deposits, and the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod are obtained through axial grid iteration calculation; The second calculation module is used to divide the corrosion deposit calculation area boundary into four parts to simulate the boron enrichment inside the corrosion deposit. The four parts include the corrosion deposit-coolant boundary, the corrosion deposit-chimney surface boundary, the corrosion deposit-cladding boundary and the corrosion deposit-corrosion deposit periodic boundary. For the temperature boundary conditions of the temperature control equation, the boundary conditions of the four parts are: , , , , where: is the equivalent thermal conductivity of the corrosion deposits, is the evaporation heat transfer coefficient of the corrosion deposit surface, T coolant is the coolant temperature, T sat is the chimney surface temperature, is the heat flux on the fuel rod, is the boundary normal direction vector, For the pressure boundary conditions of the pressure control equation, the boundary conditions of the four parts are: , , , , where: is the vaporization enthalpy of the coolant, is the coolant pressure, is the coolant density; For the concentration boundary conditions of the concentration control equation, the boundary conditions of the four parts are: , , , ; Where: C coolant is the solute concentration in the coolant; According to the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod output by the first calculation module, for each layer of corrosion deposit deposition in the axial direction, the chimney area in the corrosion deposit is modeled and meshed using the microchannel model in the second calculation module, and the temperature control equation, pressure control equation and solute concentration control equation inside the corrosion deposit are discretely solved using the finite volume method to obtain the boron concentration distribution in each axial layer of corrosion deposit. The temperature control equation inside the corrosion deposit is: , the pressure control equation inside the corrosion deposit is: , , where: is the permeability of the dirt deposits, is the dynamic viscosity of the coolant; the concentration control equation inside the corrosion deposit is: , where: is the diffusion coefficient of the solute in the solvent; T is the temperature; P is the pressure; C is the concentration; is the flow field velocity vector; The third calculation module is used to integrate the corrosion deposit thickness distribution obtained in the first calculation module and the boron concentration distribution obtained in the second calculation module to generate the input file required by the open source neutron calculation software OpenMC. The axial power distribution of the fuel rod is obtained by calculation using the Monte Carlo method, and the scale-induced axial power offset value AO is calculated according to the following formula: , where: is the power integral of the upper half of the fuel rod, is the power integral of the lower half of the fuel rod.

2. The method for calculating the risk of axial power deviation caused by fouling in a pressurized water reactor according to claim 1, characterized in that: Also includes: If the scale-induced axial power offset value is not greater than the set safety threshold, the third calculation module is used to input the scale-induced axial power offset value into the first calculation module to perform the scale-induced axial power offset coupling operation for the next time step; if the scale-induced axial power offset value is greater than the set safety threshold, the third calculation module is used to issue an alarm and end the simulation.

3. A coupled calculation device for the risk of axial power deviation caused by fouling in a pressurized water reactor, characterized in that: comprising a first computing module, a second computing module and a third computing module, The first calculation module is used to simulate the thickness deposition of corrosion deposits, and obtain the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod through axial grid iteration calculation; The second calculation module is connected to the first calculation module and is used to divide the corrosion deposit calculation area boundary into four parts to simulate the boron enrichment inside the corrosion deposit, the four parts including the corrosion deposit-coolant boundary, the corrosion deposit-chimney surface boundary, the corrosion deposit-cladding boundary and the corrosion deposit-corrosion deposit periodic boundary. For the temperature boundary conditions of the temperature control equation, the boundary conditions of the four parts are: , , , , where: is the equivalent thermal conductivity of the corrosion deposits, is the evaporation heat transfer coefficient of the corrosion deposit surface, T coolant is the coolant temperature, T sat is the chimney surface temperature, is the heat flux on the fuel rod, is the boundary normal direction vector, For the pressure boundary conditions of the pressure control equation, the boundary conditions of the four parts are: , , , , where: is the vaporization enthalpy of the coolant, is the coolant pressure, is the coolant density, For the concentration boundary conditions of the concentration control equation, the boundary conditions of the corrosion deposit-coolant boundary are: , , , , where: C coolant is the solute concentration in the coolant, According to the axial coolant temperature distribution of the fuel rod and the axial corrosion deposit thickness distribution of the fuel rod output by the first calculation module, for each layer of corrosion deposit deposition in the axial direction, the chimney area in the corrosion deposit is modeled and meshed using a microchannel model, and the temperature control equation, pressure control equation and solute concentration control equation inside the corrosion deposit are discretely solved using the finite volume method to obtain the boron concentration distribution in each axial layer of corrosion deposit. The temperature control equation inside the corrosion deposit is: , the pressure control equation inside the corrosion deposit is: , , where: is the permeability of the dirt deposits, is the dynamic viscosity of the coolant; the concentration control equation inside the corrosion deposit is: , where: is the diffusion coefficient of the solute in the solvent, T is the temperature, P is the pressure, C is the concentration, is the flow field velocity vector; The third calculation module is connected to the first calculation module and the second calculation module, and is used to integrate the corrosion deposit thickness distribution obtained in the first calculation module and the boron concentration distribution obtained in the second calculation module, generate the input file required by the open source neutron calculation software OpenMC, calculate the axial power distribution of the fuel rod by using the Monte Carlo method, and calculate the scale-induced axial power offset value AO according to the following formula: , where: is the power integral of the upper half of the fuel rod, is the power integral of the lower half of the fuel rod.

4. An electronic device, characterized in that: include: A processor, used to execute the method for calculating the risk of axial power deviation caused by fouling in a pressurized water reactor according to claim 1 or 2; as well as A memory is used to store executable instructions of the processor.

5. A computer-readable storage medium having computer executable instructions stored thereon, characterized in that: When the executable instructions are executed by the processor, the method for calculating the risk coupling of axial power deviation caused by fouling in a pressurized water reactor as described in claim 1 or 2 is implemented.

6. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, a method for calculating the risk coupling of axial power deviation caused by fouling in a pressurized water reactor as described in claim 1 or 2 is implemented.

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